18 HICKS, ON GONIDIA OF LICHENS. 



particular witli the marks of the genus Coccochloris, Has- 

 sall, and seem visually identical with C. Brebissonii. I 

 have not had any opportunity of testing whether they, like 

 itj possess the property of conjugating ; it is an interesting 

 question for future investigators ; nor is such a process hy 

 any means impossible, when it is remembered that it is 

 merely an act of fusion, not of impregnation. 



It will be seen that the mass (" frond") is at first definite, 

 but becomes indefinite as soon as the common envelope is 

 broken up or dissolved. After this these Palmoglaea-cells 

 may multiply as Pahnoglcece, till a large mass is formed, and 

 then, circumstances changing, the cell-development proceeds 

 in one of the other modes, which will account for the mass fre- 

 quently possessing more or less of a uniform character through- 

 out its whole extent. I have seen cells precisely similar to 

 these amongst aquatic algae, and which are possibly of the 

 same origin. I saj possibly because, from observations in 

 other directions, I have good reason to believe that other 

 vegetable organisms do, in some of their phases, form masses 

 of Gleocapsa-like cells. 



What other changes take place under varying circumstances 

 in the Cladonia-gonidium it is impossible to say, but I am 

 disposed to consider that by no means have all been noticed. 

 Nor are they confined to Cladonia alone ; I have found all 

 the early changes sparingly in Lecanora, Parmelia, and one 

 or two others : also the Paltnoglcea-gro'wth. in Parmelia ; and 

 it is very probable that future observations may extend it to 

 many others, for I shall, in a future contribution, show that 

 there is considerable tendency in the gonidium to vary in 

 other dii'ections than those just mentioned. 



The next point I wish to remark upon is, that about and 

 amongst these masses of Gleocapsa, Palmoglcea, &c., fine fibres 

 are to be found (tubular, jointed occasionally, and branching), 

 which dip in between the component masses and cells, as I 

 have drawn in figs. 11, 14 c, 17 a, and 18 ; such have also been 

 noticed to exist in the masses classed under Palmellacese, and 

 supposed by Thwaites"^ and others to belong to the cells. 

 Under the belief that the Palmellacese were distinct algte, 

 their existence was very inexplicable, and their connection 

 doubted. From the above remarks, however, the matter will, 

 I think, be very easy of solution, for, as I noticed in the 

 former fasciculus, the branches of the fibre of the soridium 

 passed inwards, between the segments of the soridium. Xow, 

 when the Gleocapsa-formation takes place, these fibres (pro- 



* ' Annals of Natural History,' Second Series, vol. iii, pp. 241, 243. 



